Two processes are essentially known for the dressing of grinding worms.
On the one hand, dressing using a profile roller dresser. In this case, dressing takes place with line contact between the profile roller dresser and the worm. The advantage of this process can be found in the short dressing times which can be further cut with two-flank dressing. In methods known from the prior art for dressing using a profile roller dresser, there is, however, the disadvantage that, with a given dresser, the profile shape can only be influenced with limitations during the dressing process.
A further method of dressing known from the state of the art is contour dressing. In contrast to dressing using a profile roller dresser, only a small section of the profile is dressed per stroke here, which requires a plurality of strokes to dress the profile from tip to root. The process hereby becomes very uneconomic. It does, however, offer the possibility of specifying the profile shape freely within certain limits during dressing via the kinematics. If dressers are used which have a circular or elliptical profile, the profile can be given a very flexible design. However, a very large number of strokes are required due to the small contact surface and the profile has a high degree of roughness. If dressers having a short, straight profile shape are used, the number of strokes can admittedly be reduced. However, profile modifications can only be roughly approximated, whereby shape deviations arise.
The present disclosure therefore looks at methods of dressing which work in accordance with the first variant, i.e. in which there is line contact between the dresser and the tool during dressing so that short dressing times result.
A method is known from DE102012015846A1 in which a modification of the surface geometry is produced by additional movements when dressing on the tool, said modification having a constant value in the generating pattern at least locally in a first direction on the tooth flank and being given by a function f(x) in a second direction which extends perpendicular to the first direction. A method is known from EP1995010A1 and WO 20101060596A1 of dressing a worm in a crowning manner over its width during dressing by changing the center distance. Methods are known from DE19624842A1 and DE 19706867 in which a worm whose profile angle changes over its width is produced by a constant change of the position of the dresser with respect to the tool during dressing. Methods are likewise known from DE 102005030846A1 and DE 102006061759A1 in which a worm is manufactured by corresponding working kinematics either over its total width with a constantly modified profile angle or the profile angle is modified over the worm width. A two-flank dressing for twist-free generating grinding is known from Kapp, Effizient and produktiv mit technologischer Flexibilität, JOSE LOPEZ [Kapp, Efficient and Productive with Technological Flexibility, JOSE LOPEZ].
However, in such methods in accordance with the state of the art, it was only possible to influence the profile angle, which is produced during dressing, via the dressing kinematics.
It is the object of the present disclosure to further develop a method of dressing a tool in which work is carried out with a line contact between the dresser and the tool such that the flexibility is increased with respect to the producible modifications of the surface geometry of the tool.
The present disclosure shows in a first aspect a method of dressing a tool, which can be used for the gear manufacturing machining of a workpiece, on a dresser, wherein the dressing takes place with line contact between the dresser and the tool. In this respect, a specific modification of the surface geometry of the tool is produced by the suitable choice of the position of the dresser to the tool when dressing. The method in accordance with the present disclosure in accordance with the first aspect offers a plurality of variants as to how this specific modification of the surface geometry of the tool can be specified, which will described in more detail in the following. All the variants are based on the recognition underlying the present disclosure that modifications of the surface geometry of the tool which go beyond the modification of the profile angle known from the state of the art can be reached by the specific setting of further degrees of freedom of the position between the dresser and the tool.
In accordance with a first variant, the specific modification of the surface geometry of the tool can be specified at at least three rolling angles. Alternatively or additionally, a crowning of the specific modification of the surface geometry of the tool can be specifiable. Unlike the state of the art, the present disclosure is thus not restricted to the modification of a profile angle or to the specification of the modification at two rolling angles, but rather makes possible, beyond this, a modification of the crowning or a specification at three rolling angles.
In a second variant, the specific modification of the surface geometry of the tool at at least two rolling angles and/or a pitch of the specific modification of the surface geometry of the tool can be specifiable and, in addition, an association of a specific radius of the dresser with a specific radius of the tool can take place. The association of a specific radius of the dresser with a specific radius of the tool has technical production advantages, on the one hand, for example in that an undercutting of the gearing is prevented. Alternatively or additionally, the association of the radii can, however, also be used for a direct positioning of a modification present in the dresser on the tool.
In a third variant, an association of two specific radii of the dresser with two specific radii of the tool can take place. Such an association of two radii of the dresser with two radii of the tool can, on the one hand, bring about technical production advantages. On the other hand, such an association allows an increased control of the resulting modifications and can for example when a modified dresser is used, position the modification at corresponding positions of the tool or can produce a compression or a stretching of the modification on the tool.
The geometry or association specifiable in accordance with these three variants is then produced in accordance with the present disclosure by a corresponding control (e.g., via a control system comprising a processor and non-transitory memory having instructions stored therein) of the axes of movement of the dressing machine when dressing the tool. The three variants just described can also be combined with one another.
In a fourth variant of the present disclosure in accordance with the first aspect, which is optionally combined with at least one of the first three variants, the angle of rotation of the tool and the tool width position are changed during the dressing to guide the dresser along the tool and at least two further degrees of freedom of the relative position between the dresser and the tool are set independently of one another for influencing the gearing geometry produced by the dressing and/or for associating a specific radius of the dresser with a specific radius of the tool. In accordance with the present disclosure, more degrees of freedom of the relative position between the dresser and the tool than was done in accordance with the state of the art technology are thus set independently of one another to make possible the additional modifications and/or association which are possible in accordance with the present disclosure. In this respect, at least three further degrees of freedom are optionally set independently of one another in addition to the coupling between the angle of rotation of the tool and the tool width position.
The setting of the axes of movement in accordance with the fourth variant of the present disclosure can in particular be used to produce the modifications and/or associations specified in accordance with one of the first three variants during the dressing.
Whereas a maximum of three degrees of freedom of the relative position between the dresser and the tool were used in accordance with the state of the art in order to modify the profile angle accordingly, the present disclosure is based on the recognition that additional modifications and/or associations are possible by using at least one further degree of freedom. In this respect, at least four degrees of freedom can in particular be used instead of the three degrees of freedom used in accordance with the state of the art. However, all of the available five degrees of freedom are optionally used, whereby additional possibilities arise in the specification of the modification and/or of the association.
In this respect, in a further development of the first variant, the desired modification of the tool can in particular be specified at four rolling angles. An even greater freedom in the specification of the desired modification hereby results.
Alternatively, the first variant can be further developed such that, in addition to the specification of the desired modification of the tool at three rolling angles, an association of a specific radius of the dresser with a specific radius of the tool takes place. It is thus a question of a combination of the above-named first and second variants, wherein the association of the specific radius of the dresser with a specific radius of the tool can in turn bring about technical manufacture advantages and/or can be used for positioning a modification of the dresser.
Furthermore, the two above-described variants can be combined with the third above-described variant. In this respect, in addition to the association of two specific radii of the dresser with two specific radii of the tool, a specification of the specific modification of the surface geometry of the tool at at least two rolling angles and/or a specification of a pitch of the specific modification of the surface geometry of the tool can take place. The advantages already named above also result here.
In accordance with the present disclosure, the specification of the specific modification of the surface geometry of the tool can take place by the specification of a desired modification of the surface geometry of a workpiece to be machined using the tool. In this respect, a desired modification of the surface geometry of a workpiece to be machined can in particular first be specified and the modification of the surface geometry of the tool required for the desired modification can be determined from this desired modification of the surface geometry of the workpiece to be machined using the tool. In this respect the specifications of the surface geometry which were described above with respect to the surface geometry of the tool are optionally replaceable with corresponding specifications of the surface geometry of the workpiece or are defined by them.
The relative position between the dresser and the tool required for this purpose is further optionally calculated from the modification of the surface geometry of the tool specified in accordance with the present disclosure and/or of the association of the radii in accordance with the present disclosure.
In accordance with a possible variant of the present disclosure, the specific modification of the surface geometry of the tool or the desired modification of the surface geometry of the workpiece can be a simple profile modification. In this case, only the angle of rotation of the tool and the tool width position are changed during dressing to guide the dresser along the tool, while the remaining degrees of freedom are not changed during the dressing process, but are rather set fixed for the generation of the desired profile modification and/or the association of the radii.
The present disclosure in a second aspect also comprises a method, independently of the above-named method in accordance with the first aspect, for the modified dressing of a tool, which can be used for the gear manufacturing machining of a workpiece, on a dressing machine, wherein the method comprises the following steps:                specifying a desired profile modification of the tool; and        setting the axes of movement of the dressing machine for influencing the relative position between the dresser and the tool during the dressing in dependence on the desired profile modification.        
Provision is made in accordance with the present disclosure that a modified dresser is used and the produced profile modification of the tool results from the profile modification of the dresser and from the set axes of movement of the dressing machine. In accordance with the present disclosure, the modification of the surface geometry of the tool by a corresponding setting of the relative position between the dresser and the tool during the dressing is combined with a profile modification which results from the modification of the shape of the dresser.
The present disclosure thus substantially expands the possibilities for use of modified dressers. It is possible, on the one hand, to add an additional modification to the profile modification produced by the modified dresser in order hereby to achieve a desired modification. Alternatively or additionally, it is possible to use a modified dresser for a tool for which the dresser was actually not designed in that the relative position between the dresser and the tool is correspondingly adapted during the dressing. A modified dresser can furthermore thus be adapted to the diameter of the tool changing by multiple dressing.
In accordance with a possible embodiment of the second aspect, a curve fitting can be used to determine a relative position between the dresser and the tool during the dressing by which the desired profile modification can be at least approximately generated.
Provision can furthermore be made that the portion of the profile modification of the tool produced by the setting of the axes of movement of the dressing machine is specified or determined at at least one rolling angle, and optionally at two or three rolling angles. Provision can furthermore be made that a desired position of the profile modification of the dresser on the tool is specified or determined.
Alternatively or additionally, a desired stretching or compression of the profile modification of the dresser on the tool can be specified or determined. The profile modification produced by the dresser can hereby in particular be stretched or compressed for the case that the profile modification produced by the modified dresser does not correspond to the desired modification. This can in particular take place by an association in accordance with the present disclosure of two radii of the dresser with two radii of the tool.
Alternatively or additionally, a suitable profile angle of the tool can be selected. This is based on the recognition that the same gearing can be ground with different profile angles of the tool. The profile angle of the tool can therefore likewise be set in order thus to have available a further degree of freedom in the specification or generation of modification. A stretching or compression of the profile modification of the dresser can in particular be at least partly compensated, if it is not desired, by the selection of a suitable profile angle.
In this respect, the method in accordance with the present disclosure for producing a profile modification in accordance with the second aspect can further optionally be configured as has already initially been described with respect to the first aspect.
Embodiments of the first and second aspects in accordance with the present disclosure will be shown in the following:
A relative position between the dresser and the tool during dressing, by which the specified modifications and/or associations can be exactly reached is optionally calculated from the modifications or associations specified in accordance with the present disclosure. If the modifications are specified at two, three or four rolling angles, the relative position between the dresser and the tool is optionally calculated such that the modification is produced exactly at these rolling angles. The inventor of the present disclosure has recognized that the modification resulting in the region between these rolling angles can be described in a very good approximation as an interpolation of the specified modification at the two, three or four rolling angles. In accordance with the present disclosure, the modification can admittedly thus not be exactly specified over the total profile height, but due to the specification at two, three or four rolling angles can be specified exactly there and can otherwise be specified in a good approximation.
The specifications or associations in accordance with the present disclosure can furthermore only be specifiable within certain limits. Data can in particular be calculated with respect to the gearing geometries which can be produced using the dresser on the tool, in particular minimal and/or maximal values, and can be used for restricting the specifiable values.
As described above, a simple profile modification of the tool can be produced in accordance with the present disclosure. The present disclosure is, however, not restricted to the production of simple profile modifications, but can rather also produce modifications which vary over the tool width.
In accordance with the present disclosure, the specific modification of the surface geometry of the tool or the desired modification of the surface geometry of the workpiece can be specifiable at at least one rolling angle as a function of the tool width position. In this respect, the specific modification of the surface geometry of the tool or the desired modification of the surface geometry of the workpiece can be specifiable at two or three rolling angles as a function of the tool width position. The present disclosure thus allows a variety of topological modifications.
In accordance with the present disclosure, the setting of the axes of movement of the dressing machine can take place in dependence on the tool width position to produce the specific modification. The relative position between the dresser and the tool during dressing can be selected differently for different tool width positions in accordance with the present disclosure in order hereby to produce different specific modifications in the profile direction in dependence on the tool width position.
The association of a specific radius of the dresser with a specific radius of the tool can furthermore be specified in accordance with the present disclosure as a function of the tool width position. This is in particular of advantage when a modified dresser is used. The association of a specific radius as a function of the tool width position thus allows the modification of the dresser in the tool width direction to be mapped at different positions. If the modification of the dresser has an edge, for example, the progression of this edge can be set over the tooth flank in accordance with the present disclosure. In accordance with the present disclosure, the setting of the axes of movement of the dressing machine can thus take place in dependence on the tool width position to produce the desired association.
At least one of the rolling angles at which the modification can be specified can furthermore be selected differently in the tool width direction in accordance with the present disclosure. This rolling angle can in particular be specifiable as a function of the tool width position. Such a selection of the rolling angle at which the modification can be specified as different in the tool width direction thus allows those points at which the modification is exactly produced to be selected differently in the tool width direction. In accordance with the present disclosure, two, three or four rolling angles at which the modification can be specified can be selected differently in the tool width direction and can in particular be specified as a function of the tool width position.
The present disclosure can be used both in single-flank dressing and in two-flank dressing. However, additional possibilities of influencing the modifications naturally result in single-flank dressing which are not present in two-flank dressing due to the existing dependencies between the modifications on the left flank and on the right flank.
In accordance with the present disclosure, the dressing can take place on a single flank in a possible variant and the at least three or four specifiable rolling angles can be arranged at one flank. Alternatively, the dressing can take place at two flanks and the at least three or four rolling angles can be distributed over the two flanks. For example, the dressing can thus take place at two flanks and different profile angles can be specified at both flanks. Dressing, in contrast, optionally takes place at one flank for the specification in accordance with the present disclosure of a desired crowning.
In a further development of the present disclosure, dressing can take place at two flanks and a tool having a conical basic shape can be used. Additional possibilities for setting the modification hereby result. In this respect, the conical angle of the tool can be used for setting the desired modification. An additional degree of freedom is available with the conical angle to influence the modification differently at the left and right flanks.
In a possible embodiment of the present disclosure, a modification produced by modifying the dresser can have a specific modification of the surface geometry of the tool superimposed on it which is produced by the setting of the position of the dresser with respect to the tool during dressing. For example, for the case that no dresser is available which would produce a desired modification with a normal setting of the axes of movement, this desired modification can thus be achieved by a superimposition of a modification produced by the setting of the position of the dresser with respect to the tool.
The position of the modification at the tooth flank produced by a modification of the dressier is optionally specifiable. The position of the dresser relative to the tool is in particular set such that the modification produced by the modification of the dresser is positioned at a desired position at the tooth flank. This is in particular of importance when the modification of the dresser does not extend uniformly over the total tooth depth, but rather has pronounced points such as an edge.
In a possible further development of the present disclosure, the position of the modification of the tooth flank of the tool produced by a modification of the dresser can be specifiable as a function of the position in the tool width direction. It is hereby possible to vary the position of the modification in the tool width direction and, for example, to produce a progression of the position of the edge produced by the dresser which varies in the tool width direction.
In a possible embodiment, the position of the modification at the tooth flank of the tool produced by a modification of the dresser can be specified or defined in that an association of a specific radius of the dresser with a specific radius of the tool takes place.
It is furthermore conceivable to specify a desired stretching or compression of the modification of the dresser at the tool. A corresponding stretching or compression of the modification can also hereby be selected by the setting of the position of the dresser with respect to the tool for the case that the modification of the dresser does not correspond to the desired modification.
It is possible to specify the stretching or compression of the modification as a function of the position in the tool width direction. A variation of the modification in the width direction is hereby possible.
The specification or definition of the desired stretching or compression of the modification of the dresser optionally takes place in that two specific radii of the dresser are associated with two specific radii of the tool.
In a possible embodiment of the present disclosure, a suitable profile angle of the tool can furthermore be selected. The profile angle can hereby in particular be varied for the case that an unwanted stretching or compression of the modification of the dresser at the tool results with the normal profile angle of the tool in order to achieve a desired stretching or compression of the modification. The tool can in particular be furnished with a profile angle which, together with the selected position of the dresser relative to the tool, produces a desired stretching or compression of the modification of the dresser or prevents an unwanted stretching or compression of the modification of the dresser.
In a possible embodiment of the present disclosure, the modified dresser can have an unchanging modification over its complete, active profile. An unchanging crowning can, for example, be provided over the complete, active profile.
In an alternative embodiment, the modified dresser can, however, have a modification in at least a part region of its profile which differs from the profile shape in at least one second part region. In this respect, more than two part regions having different modifications can also be provided. The modification can furthermore have a different profile angle and/or a different crowning in the first part region than the modification in the second part region. The modification in the first part region and/or in the transition between the first and second part regions can in particular have an edge.
The first and second part regions of the dresser are optionally simultaneously in contact with the tool surface during dressing. Respective different modifications can hereby be produced in only one stroke in both part regions during dressing. If the dresser has more than two part regions, all the part regions are optionally simultaneously in contact with the surface of the tool during dressing. The part regions of the dresser can optionally substantially cover the total tooth depth of the tool so that dressing takes place over the total tooth depth in one stroke.
In accordance with the present disclosure, a combination dresser can be used for a simultaneous dressing of the addendum and of the tooth flank. In this case, the height of the addendum can optionally be specified and can be produced by setting the axes of movement of the dressing machine during dressing. This can in particular take place by a corresponding association of a radius of the dresser with a radius of the tool. In a possible embodiment of the present disclosure, the height of the addendum can be specifiable as a function of the tool width position. The height of the addendum can hereby be varied over the tool width.
In possible embodiments of the present disclosure, the dressing machine can have more axes of movement than there are geometrical degrees of freedom in the setting of the relative position between the dresser and the tool. In this case, a plurality of settings of the axes of movement of the dressing machine which produce a relative position can be present for this specific desired relative position between the dresser and the tool.
In accordance with the present disclosure, a setting is optionally chosen from a plurality of settings of the axes of movement of the dressing machine which produce the same relative position between the dresser and the tool which better satisfies specified conditions. A setting can in particular be chosen which provides the desired relative position with a higher accuracy and/or with smaller positional errors. It can in particular be taken into account that the accuracy of the axes of movement can differ in dependence on the specific position of the axes of movement. A setting can furthermore be chosen which requires smaller travel movements of the machine aides. Kinematic aspects can in particular thus also be taken into account during the machining process, in particular when a position of the dresser is used which varies over the face width of the tool.
A setting can furthermore be chosen which avoids mutual collisions of the dresser, the tool and/or the machine parts. It must in particular be taken into account that the travel movements of the machine axle which may be necessary in accordance with the present disclosure to produce the desired modifications can be substantially higher than the travel movements of the machine axles typically necessary as part of a dressing process. In accordance with the present disclosure, the settings are therefore optionally selected such that collisions are nevertheless avoided.
In accordance with a possible embodiment of the present disclosure, the gear tooth geometry produced on the tool by the dressing and/or the gear tooth geometry produced on the workpiece by the tool can be measured and the differences of the axes of movement of the dressing machine from their desired positions which are present during dressing can be determined from differences from a desired geometry. Such differences of the axes of movement from their desired positions can be recognized and corrected by such a procedure.
In accordance with the present disclosure, at least three of the degrees of freedom present can optionally be used to produce the desired modification during the relative positioning between the dresser and the tool. Four or five degrees of freedom are optionally used. The degrees of freedom are further optionally set independently of one another to produce the desired modification.
The degrees of freedom which can be set in accordance with the present disclosure can in particular be three, four or all of the following five degrees of freedom: Angle of rotation of the tool; axial position of the tool; y position of the dresser; center distance; and/or axial cross angle. These degrees of freedom are geometrical degrees of freedom which can be provided by the control of different axes of movement in dependence on the embodiment of the dressing machine.
The axial position of the tool, i.e. the tool width position, can in particular be used in accordance with the present disclosure to displace the contact line of the dresser. Two, three of four degrees of freedom of the remaining four degrees of freedom are optionally set independently of one another to produce the specific modification along the contact line.
The method in accordance with the present disclosure opens up a plurality of possible cases of application.
Errors in the surface geometry of a dresser can, for example, be corrected at least partly or completely in accordance with the present disclosure by specifying corresponding correction values in the setting of the axes of movement of the dressing machine. An incorrectly produced dresser therefore does not first have to be reworked in an elaborate manner, but can rather be corrected by a correction of the relative position between the dresser and the tool.
In a further possible application of the present disclosure, a dresser which has been designed for a tool having a first macrogeometry and/or a first desired surface geometry can be used for dressing a tool having a second macrogeometry and/or a second desired surface geometry. The present method thus allows dressers to be used not only for those tools for which the dresser was actually designed, but rather also for tools having a different macrogeometry. Alternatively, a dresser can be used for a tool having a macrogeometry for which it was also designed, but would produce a different surface geometry than that which was intended in the design of the dresser due to the modification in accordance with the present disclosure.
The errors in the dressing of the second tool resulting from the design for the tool having the first macrogeometry and/or the first desired surface geometry can in particular be at least partly or completely compensated in accordance with the present disclosure by a corresponding setting of the axes of movement of the dressing machine when dressing the tool having a second macrogeometry and/or a second desired surface geometry.
A typical application case is the small-batch production of a plurality of different gear wheels having a different gearing geometry. In accordance with the present disclosure, it is no now longer necessary to prepare a specific new dresser for each application case. It is rather the case that that dresser can be selected from an existing range of dressers which best matches a new grinding job and differences from the desired geometry which are still present can be compensated by setting the axes of movement.
Errors which result from the tool diameter reducing in the multiple dressing of the same tool can furthermore likewise be compensated in accordance with the present disclosure by a corresponding change of the relative position between the dresser and the tool. Unlike the state of the art, a dresser can hereby not only be used for a tightly limited diameter range of a tool, but this diameter range can be substantially extended.
In a possible embodiment of the present disclosure, the setting of the axes of movement of the dressing machine during the dressing and/or the macrogeometry of the dresser and/or the modification of the dresser and/or the macrogeometry of the tool can be determined by means of a curve fitting. With a fixed macrogeometry and/or modification of the dresser and a desired modification of the tool, for example, a suitable setting of the axes of movement of the dressing machine during dressing and/or a suitable macrogeometry of the tool can be determined by means of a curve fitting. The settings of the axes of movement of the dressing machine during dressing are optionally always determined as part of the curve fitting.
The modifications in the generating pattern which can be achieved as part of the curve fitting by the change of the setting of the axes of movement of the dressing machine in a direction having an angle ρFS with respect to the tool width direction can furthermore optionally be varied at two, three or four rolling angles and can be interpolated in their direction and can optionally be assumed as linear, quadratic and/or cubic functions. Such an achievable modification is then optionally compared with a desired modification. In this respect, a distance function can be used for quantifying the difference. In a possible embodiment, the distance function can have a weighting dependent on the position in the generating pattern. It can in particular hereby be taken into account that the tolerances for difference positions in the generating pattern can be of different amounts.
In a possible embodiment of the present disclosure, a tool can be used with which at least one thread is inactive and/or omitted. It can hereby be taken into account in accordance with the present disclosure that the changes in the position of the dresser with respect to the tool in accordance with the present disclosure may have to be relatively large in part in order to generate the desired modifications. It can occur in this case that the dresser at least partly engages into the contour of the oppositely disposed flank when dressing a first flank. If at least one thread is inactive and/or omitted, there is hereby more room for the dresser during dressing.
In accordance with the present disclosure, a tooth flank can be dressed for this purpose such that it does not come into contact with the workpiece on the machining of the workpiece and is therefore inactive. It is hereby of no significance if this thread accidentally moves into contact with the dresser when dressing the oppositely disposed flank and is therefore given an unwanted contour. In this respect, at least one thread is optionally dressed such that it does not come into contact with the workpiece on the machining of the workpiece and is therefore inactive.
In an embodiment, at least one inactive and/or omitted thread is provided between two active threads. There is hereby respectively more space for the dresser for the dressing machining of the flanks of the active threads since at least one inactive and/or omitted thread is provided between the two active threads.
On the machining of a workpiece using such a tool in generating coupling, a maximum of every second tooth of the workpiece comes into engagement with the tool after one another in a possible embodiment of the present disclosure. This is due to the fact that at least one inactive and/or omitted thread is optionally provided between two active threads so that the tooth of the workpiece associated with this inactive or omitted thread remains omitted during the machining.
In accordance with the present disclosure, a first portion of the teeth of the workpiece can be machined in dependence on the number of teeth of the workpiece and/or on the number of starts of the workpiece in at least one first pass, whereupon the workpiece is rotated relative to the tool to machine at least one second portion of the teeth in at least one second pass. It is hereby ensured that all the teeth of the workpiece are also actually machined. In this respect, more than two passes can optionally also be used to machine the teeth of the workpiece.
In a first variant of the present disclosure, the dressing can take place with a line contact to the dresser extending over the total tooth depth of the workpiece and the total tooth depth can thus be dressed in one stroke.
In a further variant of the present disclosure, the dressing can take place in two or more strokes with respective line contact. Unlike with contour dressing, however, work is carried out here with line contact and thus with relatively few strokes. However, a plurality of strokes are used over the tooth depth to achieve an even higher flexibility with regard to the modification of the tool surface.
In this respect, the axes of movement of the dressing machine are set differently during dressing in the respective stroke in addition to the change of the position required for the different positioning between the dresser and the tool with the two or more strokes. The pitch and/or crowning of the modification in the at least one of the strokes can in particular be influenced by a corresponding change of the relative position between the dresser and the tool.
To the extent that as part of the present application a pitch of the modification is spoken of, this is actually, in accordance with the customary choice of words within the field of gear machining, the profile angle or the profile angle error. The term pitch is, however, chosen to be able better to illustrate the geometrical relationships since the profile angle is the pitch of the tooth flank in the vertical direction.
In accordance with the present disclosure, the specific modification can be set in at least one of the strokes such that the surface geometry produced by the at least one first stroke adjoins the surface geometry produced by at least one second stroke at a desired angle and in particular tangentially. A tangential transition is hereby ensured between the regions dressed by the individual strokes. In accordance with the present disclosure, the roughness of the machined surface present in contour dressing is thus avoided as part of the present disclosure. The modifications for all strokes can in particular be set such that the surface geometries produced by the individual strokes adjoin the surface geometries produced by the adjacent strokes at a desired angle and in particular tangentially.
In this respect, a desired modification of the tool is optionally specified at at least two, and optionally at three, rolling angles for at least one stroke, and further optionally for every stroke. An association of a specific radius of the dresser with a specific radius of the tools is further optionally carried out for at least one stroke and optionally for every stroke. The regions which are swept over by the respective strokes are defined by the association of the radii. On the one hand, the tangential adjoining at the adjacent strokes can be achieved by the specification of the desired modification of the tool at at least two, and optionally at three, rolling angles and, on the other hand, a desired crowning can, for example, be specified singly for every stroke.
In accordance with a possible embodiment of the present disclosure, different regions of the dresser can be used for the different strokes. Alternatively or additionally, different dressers can also be used for the individual strokes. This makes it possible additionally to produce additional modifications by differently modified regions of the dresser or by differently modified dressers by the different modification produced by the setting of the machine axles.
In a possible application of the present disclosure, one of the strokes can be used for producing a modification of the dedendum (e.g., the radial distance from the pitch circle of the gear wheel to the bottom of the tooth space or groove) or of the addendum (e.g., the height by which a tooth of the gear wheel projects beyond the standard pitch circle or pitch line, or the radial distance between the pitch diameter and the outside diameter), for example for producing a relief of the addendum or of the dedendum. A second stroke can be used, for example, for dressing the tooth flank.
In accordance with a further variant of the present disclosure, the position or the positions at which the modifications produced by the respective strokes adjoin one another can also be varied in dependence on the tool width position. An additional flexibility in the variation of the modification in the tool width direction hereby results.
In accordance with the present disclosure, at least one of the strokes used takes place in accordance with a method in accordance with the present disclosure. All the strokes, however, optionally take place in accordance with a method in accordance with the present disclosure. In this respect, the individual strokes can be used for producing a simple profile modification. Alternatively, however, one or more strokes can also be used for producing a topological modification, e.g. the modification in the tool width direction can vary.
In addition to the method in accordance with the present disclosure for dressing a tool, the present disclosure furthermore comprises a method for producing a workpiece with a modified gearing geometry by a generation method by means of a modified tool, wherein a specific modification of the surface geometry of the tool is produced by a dressing method in accordance with the present disclosure and the specific modification of the tool by the generation method produces a corresponding modification on the surface of the workpiece. A diagonal generating method can in particular be used for machining the workpiece. It is possible by such a diagonal generating method to map a topological modification of the surface geometry of the tool on the workpiece. A modification of the surface geometry of the tool varying in the width direction in accordance with the dressing method in accordance with the present disclosure can in particular be used to produce a corresponding variation of the modification of the workpiece in the workpiece width direction by a diagonal generating method. The diagonal generating method maps the variation of the tool on the surface of the workpiece. The present disclosure can, however, also be used for producing a simple profile modification of the workpiece. In this case, an axial generating method is optionally used for producing the workpiece.
In this respect, a desired modification of the surface geometry of a workpiece to be machined using the tool can be specified and the specific modification of the surface geometry of the tool required for its manufacture can be determined from it. In this respect the specifications of the surface geometry which were described above with respect to the surface geometry of the tool are optionally replaceable with corresponding specifications of the surface geometry of the workpiece or are defined by them.
In addition to the method in accordance with the present disclosure, the present disclosure furthermore comprises an apparatus and/or a software program for calculating the relative position between the dresser and the tool required for producing a desired modification of a tool on dressing in line contact with a specified dresser or for calculating the settings of the axes of movement of a dressing machine required for their provision. The present disclosure claims protection both for the apparatus and for the software program per se and independently of one another. In a possible embodiment of the present disclosure, the software program can, however, also be worked through on the apparatus in accordance with the present disclosure. The software program can, however, also be stored on a data carrier or in a memory, for example. The apparatus can in particular be a computer and/or a machine control. A software program in accordance with the present disclosure can optionally run thereon.
The apparatus in accordance with the present disclosure or the software program in accordance with the present disclosure comprises an input function by which the specific modification of the surface geometry of the tool is specifiable and a calculation function which determines the relative position between the dresser and the tool required for the production of the modification when dressing with line contact between the dresser and the tool or the settings of the axes of movement of the dressing machine required for the provision of the modification from the specific modification.
In a first variant, the input functions and the calculation function can be configured such that they can be used for carrying out one of the methods in accordance with the present disclosure described in more detail above. In this respect, the apparatus or the software program overall can optionally serve the carrying out of a method in accordance with the present disclosure or can be usable as part of such a method.
In a second variant, the input function and the calculation function can be configured such that the specific modification of the surface geometry of the tool is specifiable at at least three rolling angles and can be produced by the calculated relative position or setting of the axes of movement of the dressing machine. Alternatively or additionally, the input function and the calculation function can be configured such that a crowning of the gearing is specifiable and can be produced by the calculated relative position or setting of the axes of movement of the dressing machine.
In a further variant, the input function and the calculation function can be configured such that the specific modification of the surface geometry of the tool is specifiable at at least two rolling angles and can be produced there by the calculated relative position or setting of the axes of movement of the dressing machines and, in addition, an association of a specific radius of the dresser with a specific radius of the tool can be specified or calculated and takes place based on the calculated relative position or setting of the axes of movement of the dressing machine.
In a further variant, the input function and the calculation function can be configured such that a pitch of the modification of the gearing is specifiable and can be produced by the calculated relative position or setting of the axes of movement of the dressing machine and, in addition, an association of a specific radius of the dresser with a specific radius of the tool can be specified or calculated and takes place based on the calculated relative position or setting of the axes of movement of the dressing machine.
In a further variant, the input function and the calculation function can be configured such that an association of two specific radii of the dresser with two specific radii of the tool takes place.
In a further variant, the input function and the calculation function can be configured such that data with respect to a modified dresser can be input and a determination unit (e.g., which is a unit of a software program and/or which comprises a set of instructions stored in non-memory of a control system which are executable by a processor of the control system) determines the setting of the axes of movement of the dressing machine such that a desired profile modification of the tool is produced at least approximately and optionally exactly from the profile modification of the dresser and from the set axes of movement of the dressing machine.
The input function and the calculation function are optionally configured such that a plurality of the above-named variants are implemented. The user can therefore optionally select from a plurality of these variants provided by the input function and the calculation function. The input function and the calculation function optionally provide at least two, further optionally at least three or at least four, of the above-named variants.
The input function in accordance with the present disclosure and the calculation function are optionally each configured such that they can be used for carrying out a method in accordance with the present disclosure. The specification or the calculation in particular takes place such as already shown above in more detail with respect to the method in accordance with the present disclosure.
The input function can, for example, be configured such that a desired modification of the surface geometry of the workpiece which is to be machined using the tool is specifiable, wherein the input function generates the above-named data for the specific modification of the surface geometry of the tool from this.
The present disclosure furthermore comprises a dressing machine or a gear-cutting machine having a dressing machine, wherein the dressing machine has a tool holder for holding the tool to be dressed and a dresser holder for holding the dresser used for this purpose. The dresser holder has an axis of rotation, wherein the dressing machine has further axes of movement by which further degrees of freedom can be set independently of one another during the dressing of the tool in line contact with the dresser. The tool holder optionally also has an axis of rotation. The dressing machine or the gear-cutting machine has a control which is configured in accordance with one of the following variants:
In a first variant, the control controls the axes of movement of the dressing machine such that the angle of rotation of the tool and the tool width position are varied during the dressing to guide the dresser along the tool, wherein at least two further degrees of freedom of the relative position between the dresser and the tool can be set and/or controlled and/or specified independently of one another for influencing the gear tooth geometry produced by the dressing.
In the further variants described in the following, the control respectively has an input function by which the specific modification of the surface geometry of the tool can be specified and a calculation function which determines the settings of the axes of movement required for generating the specific modification during the dressing with line contact between the dresser and the tool from the specific modification. The control furthermore has a control function which carries out a corresponding setting of the axes of movement during the dressing with line contact between the dresser and the tool.
In a variant, the input function, the calculation function and the control function can each be configured such that they can be used for carrying out one of the aforesaid methods.
In a further variant, the input function, the calculation function and the control function can be configured such that the specific modification of the surface geometry of the tool is specifiable at at least three rolling angles and is produced there by the setting of the axes of movement of the dressing machine. Alternatively or additionally, the configuration can take place such that a crowning of the gearing is specifiable and is produced by the setting of the axes of movement of the dressing machine.
In a further variant, the input function, the calculation function and the control function can be configured such that the specific modification of the surface geometry of the tool is specifiable at at least two rolling angles and is produced there by the setting of the axes of movement of the dressing machine and, in addition, an association of a specific radius of the dresser with a specific radius of the tool is specifiable or is calculated and takes place by the setting of the axes of movement of the dressing machine.
In a further variant, the input function, the calculation function and the control function can be configured such that a pitch of the modification of the gearing is specifiable and is produced by the setting of the axes of movement of the dressing machine and, in addition, an association of a specific radius of the dresser with a specific radius of the tool is specifiable or is calculated and takes place by the setting of the axes of movement of the dressing machine.
The input function, the calculation function and the control function can furthermore be configured such that an association of two specific radii of the dresser with two specific radii of the tool takes place.
In a further variant, the input function, the calculation function and the control function can be configured such that data with respect to a modified dresser can be input and the determination unit determines the setting of the axes of movement of the dressing machine such that a desired profile modification of the tool is produced at least approximately from the profile modification of the dresser and from the set axes of movement of the dressing machine.
The control can implement a plurality of the described variants, in particular as different modes of operation.
The dressing machine or gear-cutting machine in accordance with the present disclosure can optionally be configured such that they can be used for carrying out a method in accordance with the present disclosure such as described above. In this respect, the specification of the values or the determining of the axes of movement takes place such as described in more detail above. The determination and the control optionally take place automatically.
The input function, the calculation function and the control function are optionally configured such that a plurality of the variants described with respect to the methods in accordance with the present disclosure are available and one of these variants can be selected by the user.
The dressing machine or gear-cutting machine in accordance with the present disclosure optionally comprises an apparatus for calculating the relative position between the dresser and the tool required for producing a desired modification of a tool during the dressing in line contact, as described above, and/or comprises a corresponding software program such as described above.
The methods in accordance with the present disclosure are furthermore optionally carried out using an apparatus in accordance with the present disclosure and/or a software program in accordance with the present disclosure and/or a dressing machine in accordance with the present disclosure and/or a gear-cutting machine in accordance with the present disclosure.
The dressing machine can be a machine which is only used for dressing tools and has no additional function for machining workpieces using such tools. The dressing machine is, however, optionally a combination machine which allows both a machining of workpieces and the dressing. It can in particular be a gear-cutting machine having a dressing machine in accordance with the present disclosure, wherein the gear-cutting machine comprises, in addition to the dressing machine, a generating machine via which a gear manufacturing machining is possible using the tool dressed in accordance with the present disclosure. In this respect, the generating machine and the dressing machine can optionally share individual holders or axes of movement or a plurality of holders or axes of movement.
The gear manufacturing machining in accordance with the present disclosure is optionally a generating machining method, in particular a generating grinding method. A diagonal generating method is particularly optionally used.
The tool which is dressed or used in accordance with the present disclosure is optionally a grinding worm. A profile roller dresser or a form roller is optionally used as the dresser in accordance with the present disclosure.
The method in accordance with the present disclosure and the apparatus or tools in accordance with the present disclosure are optionally configured such that an involute gearing is produced in accordance with the present disclosure on the workpiece.
In accordance with the present disclosure, the relative position of the dresser to the tool during dressing with line contact can be specifically set such that the contact line between the dresser and the tool on the dresser is displaced in order hereby to influence the active profile transferred to the tool along the contact line. The desired modification on the tool is optionally hereby produced. The pitch and/or crowning along the contact line on the tool can in particular be set or varied. This contact line on the tool optionally defines the first direction of the modification on the tool.
In general, the pitch of the specific modification in the sense of the present disclosure is understood as the inclination in a first direction of the tool which includes an angle ρFS or ρF1 other than zero with respect to the tool width direction and which in particular has a portion in the profile direction, e.g. the pitch of the modification corresponds to the profile angle or to a profile angle difference.
Furthermore, a crowning of the modification in the sense of the present disclosure is understood as a crowning in a first direction which includes an angle ρFS or ρF1 other than zero with respect to the tool width direction and which in particular has a portion in the profile direction, e.g. the crowning of the modification corresponds to a profile crowning.
The present disclosure will now be explained in more detail with reference to embodiments and to drawings.